@misc{WeberDendorferSuessetal., author = {Weber, Karsten and Dendorfer, Sebastian and S{\"u}ß, Franz and Kubowitsch, Simone and Schratzenstaller, Thomas and Haug, Sonja and Mohr, Christa and Kiesl, Hans and Drechsler, J{\"o}rg and Westner, Markus and Kobus, J{\"o}rn and Schubert, Martin J. W. and Zenger, Stefan and Pietsch, Alexander and Weiß, Josef and Hinterseer, Sebastian and Schieck, Roland and Scherzinger, Stefanie and Klettke, Meike and Ringlstetter, Andreas and St{\"o}rl, Uta and Bissyand{\´e}, Tegawend{\´e} F. and Seeburger, Achim and Schindler, Timo and Ramsauer, Ralf and Kiszka, Jan and K{\"o}lbl, Andreas and Lohmann, Daniel and Mauerer, Wolfgang and Maier, Johannes and Scorna, Ulrike and Palm, Christoph and Soska, Alexander and Mottok, J{\"u}rgen and Ellermeier, Andreas and V{\"o}gele, Daniel and Hierl, Stefan and Briem, Ulrich and Buschmann, Knut and Ehrlich, Ingo and Pongratz, Christian and Pielmeier, Benjamin and Tyroller, Quirin and Monkman, Gareth J. and Gut, Franz and Roth, Carina and Hausler, Peter and Bierl, Rudolf and Prommesberger, Christian and Ławrowski, Robert Damian and Langer, Christoph and Schreiner, Rupert and Huang, Yifeng and She, Juncong and Ottl, Andreas and Rieger, Walter and Kraml, Agnes and Poxleitner, Thomas and Hofer, Simon and Heisterkamp, Benjamin and Lerch, Maximilian and Sammer, Nike and Golde, Olivia and Wellnitz, Felix and Schmid, Sandra and Muntschick, Claudia and Kusterle, Wolfgang and Paric, Ivan and Br{\"u}ckl, Oliver and Haslbeck, Matthias and Schmidt, Ottfried and Schwanzer, Peter and Rabl, Hans-Peter and Sterner, Michael and Bauer, Franz and Steinmann, Sven and Eckert, Fabian and Hofrichter, Andreas}, title = {Forschungsbericht 2017}, editor = {Baier, Wolfgang}, address = {Regensburg}, organization = {Ostbayerische Technische Hochschule Regensburg}, isbn = {978-3-9818209-3-5}, doi = {10.35096/othr/pub-1383}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-13835}, subject = {Forschung}, language = {de} } @misc{SchwanzerDietrichGadereretal., author = {Schwanzer, Peter and Dietrich, Markus and Gaderer, Matthias and Rabl, Hans-Peter}, title = {Detektion unterschiedlicher Medien in Gasoline Particulate Filter (GPF) mit Hilfe eines Radio-Frequenz (RF-) Sensors}, series = {Bayerische Wissenschaftsforum - BayWISS 2020}, journal = {Bayerische Wissenschaftsforum - BayWISS 2020}, language = {de} } @misc{SchwanzerDietrichGadereretal., author = {Schwanzer, Peter and Dietrich, Markus and Gaderer, Matthias and Rabl, Hans-Peter}, title = {Monitoring von Partikelfiltern f{\"u}r den Einsatz in Fahrzeugen mit direkt- einspritzenden Ottomotoren mit einer Radio-Frequenz (RF-) Antenne}, series = {Kolloquium des Bayerischen Wissenschaftsforum}, journal = {Kolloquium des Bayerischen Wissenschaftsforum}, language = {de} } @misc{SchwanzerDietrichHaftetal., author = {Schwanzer, Peter and Dietrich, Markus and Haft, Gerhard and Gaderer, Matthias and Rabl, Hans-Peter}, title = {Oxidation Kinetics Determination of GDI Engine Soot by a Radio-Frequency Sensor}, series = {23rd Conference on Combustion Generated Nanoparticles 2019, June 17-20, Z{\"u}rich, Switzerland}, journal = {23rd Conference on Combustion Generated Nanoparticles 2019, June 17-20, Z{\"u}rich, Switzerland}, language = {en} } @incollection{WalterSchwanzerHagenetal., author = {Walter, Stefanie and Schwanzer, Peter and Hagen, Gunter and Haft, Gerhard and Dietrich, Markus and Rabl, Hans-Peter and Moos, Ralf}, title = {Hochfrequenzsensorik zur direkten Beladungserkennung von Benzinpartikelfiltern}, series = {Automobil-Sensorik 3}, booktitle = {Automobil-Sensorik 3}, editor = {Tille, Thomas}, publisher = {Springer Vieweg}, address = {Berlin}, isbn = {978-3-662-61259-0}, doi = {10.1007/978-3-662-61260-6_7}, pages = {185 -- 208}, abstract = {In Folge der Versch{\"a}rfung der gesetzlichen Abgasnormen wurden f{\"u}r direkt-einspritzende Benzinmotoren Partikelfilter notwendig. Zur Beladungs{\"u}berwachung k{\"o}nnen aufgrund stark unterschiedlicher Rahmenbedingungen die aus Dieselmotoren bekannten Systeme, wie dem Differenzdrucksensor, nur eingeschr{\"a}nkt {\"u}bernommen werden. Ein hochfrequenzbasiertes Verfahren koppelt mittels Antennen elektromagnetische Wellen in das Filtergeh{\"a}use ein, deren Ausbreitungsverhalten durch die dielektrischen Eigenschaften des eingelagerten Rußes beeinflusst wird. Hierdurch kann bei Auswertung von Transmissionsd{\"a}mpfung oder Resonanzfrequenzen die Rußbeladung direkt detektiert werden.}, language = {en} } @misc{SchwanzerMieslingerRabletal., author = {Schwanzer, Peter and Mieslinger, Johann and Rabl, Hans-Peter and Dietrich, Markus and Haft, Gerhard and Walter, Stefanie and Hagen, Gunter and Moos, Ralf and Gaderer, Matthias}, title = {Monitoring of a Particulate Filter for Gasoline Direct Injection Engines with a Radio-Frequency-Sensor}, series = {11th International Exhaust Gas and Particulate Emissions Forum, 3.-4.3.2020, Ludwigsburg, Germany}, journal = {11th International Exhaust Gas and Particulate Emissions Forum, 3.-4.3.2020, Ludwigsburg, Germany}, abstract = {In order to comply with future emission regulations, the use of particulate filters in vehicles with direct injection gasoline engines is essential. The current amount of soot and ash in the filter is calculated by a soot load model in the electronic control unit in combination with a differential pressure sensor determining the pressure drop over the particulate filter. Active regeneration is initiated if the calculated amount of soot or the measured differential pressure is too high. This is associated with additional fuel consumption. An on-board diagnosis for the particulate filter is currently not part of the Euro 6d emission standard. For future exhaust emission standards, on-board diagnosis or active monitoring of the particulate filter is conceivable. One of the benefits of monitoring is the fact that unnecessary active regenerations can be avoided. As a result, there is no additional fuel consumption due to misinterpretations of the amount of soot in the filter. For active monitoring of the particulate filter, a radiofrequency (RF-) sensor, that detects the soot loading of the filter with electromagnetic waves directly, can be used. Such a system has the advantage that by utilizing the filter as a sensor more precise information about the current state of the filter, e.g. a possible damage, can be provided. Worst-case considerations of filter damages, tested at an engine test bench show the advantages which are entailed by a system like that. By means of partial regeneration of the particulate filter it is demonstrated how the remaining amount of soot in the filter can be detected in a better way in comparison to the differential pressure sensor by using the RF-sensor.}, language = {en} } @article{SchwanzerRablLodersetal., author = {Schwanzer, Peter and Rabl, Hans-Peter and Loders, S. and Seifert, P. and Himmelstoss, S. and Gaderer, Matthias}, title = {Difference in the Tailpipe Particle Number by Consideration of Sub-23-nm Particles for Different Injection Settings of a GDI Engine}, series = {Emission control science and technology}, volume = {5}, journal = {Emission control science and technology}, number = {1}, publisher = {Springer Nature}, doi = {10.1007/s40825-019-0114-1}, pages = {7 -- 22}, abstract = {The purpose of this study was to investigate the characteristic of nanoparticles under consideration of sub-23-nm particles from a 1.8-l direct injection (DI) gasoline engine under stoichiometric air/fuel conditions in the exhaust gas system. For future CO2 challenges, the usage of DI-instead of port fuel injection (PFI)-gasoline engines is unavoidable. Therefore, a state of the art particle management program-particle number (PN) system, the Horiba SPCS (2100) with an integrated CPC (condensation particle counter), was recalibrated from a 50\% cutoff (D-50\%) at 23 nm down to a cutoff at 10 nm and the PCRF (particle concentration reduction factor) for sizes smaller than 23 nm was checked. Two different modal points, out of a representative Real Driving Emission (RDE) cycle, were investigated with both calibrations, D-50\%=10 nm and D-50\%=23 nm. For these different load points, the fuel pressure (FUP) and the start of injection (SOI) were varied, to represent the difference in the structure and the ratio conc((10 nm))/conc((23 nm)) of the nanoparticle emissions. The particle characterization includes the particle number (PN), the particle size distribution (PSD), and the particle mass (PM). The particle number was measured with Horiba SPCS (2100). The particle size distribution was analyzed with a Grimm differential mobility analyzer (DMA) in combination with a Faraday cup electrometer (FCE). Micro Soot and Pegasor were used to determine the PM, and an optical characterization was done with a 120-kV Phillips CM12 transmission electron microscope (TEM). The position of all particle measurement systems was downstream the three-way catalyst (TWC). The results of this investigation showed that a higher injection pressure decreases the PN (without consideration of sub-23-nm particles) in general. The ratio conc((10 nm))/conc((23 nm)) was therefore higher, because smaller particles, especially ash particles, were less reduced from the FUP. This means higher FUP tends to a higher ratio. For the SOI, the main reasons of the ratio differences were explained by an encroachment between the injection jet and the piston, the valve and the wall.}, language = {en} } @article{WalterSchwanzerSteineretal., author = {Walter, Stefanie and Schwanzer, Peter and Steiner, Carsten and Hagen, Gunter and Rabl, Hans-Peter and Dietrich, Markus and Moos, Ralf}, title = {Mixing Rules for an Exact Determination of the Dielectric Properties of Engine Soot Using the Microwave Cavity Perturbation Method and Its Application in Gasoline Particulate Filters}, series = {Sensors}, volume = {22}, journal = {Sensors}, number = {9}, publisher = {MDPI}, address = {Basel}, doi = {10.3390/s22093311}, pages = {1 -- 17}, abstract = {In recent years, particulate filters have become mandatory in almost all gasoline-powered vehicles to comply with emission standards regarding particulate number. In contrast to diesel applications, monitoring gasoline particulate filters (GPFs) by differential pressure sensors is challenging due to lower soot masses to be deposited in the GPFs. A different approach to determine the soot loading of GPFs is a radio frequency-based sensor (RF sensor). To facilitate sensor development, in previous work, a simulation model was created to determine the RF signal at arbitrary engine operating points. To ensure accuracy, the exact dielectric properties of the soot need to be known. This work has shown how small samples of soot-loaded filter are sufficient to determine the dielectric properties of soot itself using the microwave cavity perturbation method. For this purpose, mixing rules were determined through simulation and measurement, allowing the air and substrate fraction of the sample to be considered. Due to the different geometry of filter substrates compared to crushed soot samples, a different mixing rule had to be derived to calculate the effective filter properties required for the simulation model. The accuracy of the determined mixing rules and the underlying simulation model could be verified by comparative measurements on an engine test bench.}, language = {en} } @article{WalterSchwanzerHagenetal., author = {Walter, Stefanie and Schwanzer, Peter and Hagen, Gunter and Haft, Gerhard and Rabl, Hans-Peter and Dietrich, Markus and Moos, Ralf}, title = {Modelling the Influence of Different Soot Types on the Radio-Frequency-Based Load Detection of Gasoline Particulate Filters}, series = {Sensors}, volume = {20}, journal = {Sensors}, number = {9}, publisher = {MDPI}, doi = {10.3390/s20092659}, pages = {1 -- 19}, abstract = {Gasoline particulate filters (GPFs) are an appropriate means to meet today's emission standards. As for diesel applications, GPFs can be monitored via differential pressure sensors or using a radio-frequency approach (RF sensor). Due to largely differing soot properties and engine operating modes of gasoline compared to diesel engines (e.g., the possibility of incomplete regenerations), the behavior of both sensor systems must be investigated in detail. For this purpose, extensive measurements on engine test benches are usually required. To simplify the sensor development, a simulation model was developed using COMSOL Multiphysics((R)) that not only allowed for calculating the loading and regeneration process of GPFs under different engine operating conditions but also determined the impact on both sensor systems. To simulate the regeneration behavior of gasoline soot accurately, an oxidation model was developed. To identify the influence of different engine operating points on the sensor behavior, various samples generated at an engine test bench were examined regarding their kinetic parameters using thermogravimetric analysis. Thus, this compared the accuracy of soot mass determination using the RF sensor with the differential pressure method. By simulating a typical driving condition with incomplete regenerations, the effects of the soot kinetics on sensor accuracy was demonstrated exemplarily. Thereby, the RF sensor showed an overall smaller mass determination error, as well as a lower dependence on the soot kinetics.}, language = {en} } @article{KoderSchwanzerZacherletal., author = {Koder, Alexander and Schwanzer, Peter and Zacherl, Florian and Rabl, Hans-Peter and Mayer, Wolfgang and Gruber, Georg and Dotzer, Thomas}, title = {Combustion and emission characteristics of a 2.2L common-rail diesel engine fueled with jatropha oil, soybean oil, and diesel fuel at various EGR-rates}, series = {Fuel}, volume = {228}, journal = {Fuel}, number = {September}, publisher = {Elsevier}, doi = {10.1016/j.fuel.2018.04.147}, pages = {23 -- 29}, abstract = {To investigate the combustion and emission behavior of straight vegetable oils (SVO), jatropha oil, soybean oil, and diesel fuel were tested. For this research, a 2.2L common-rail engine with a two-stage turbocharging concept was equipped with a cylinder pressure indication system, an exhaust-gas analyzer, an AVL Micro Soot sensor and a Scanning Mobility Particle Sizer 3936 (SMPS) device to detect the particle-size-distribution (PSD). At a low and mid-load engine-operating point (EOP), the thermodynamic and emissions were investigated under various exhaust gas recirculation (EGR) rates with respect to the PSD. Moreover, the injection behavior of the three test fuels was analyzed separately using an injection rate analyzer. This procedure facilitates the thermodynamic investigations of the engine process and allows the calculation of the hydraulic delay (HD) as well as the ignition delay (ID). The ID of the SVO fuels compared to diesel fuel was found to be lower at all engine-operating modes, while jatropha oil always showed the shortest ID. In the particulate-nitrogen oxide (NOX) trade-off, the SVO fuels showed higher particulate matter (PM) emissions at the low-load EOP, whereas the PM emissions of diesel fuel overtop the SVO fuels at a higher engine load. With increased EGR-rates, a rise in the particle size was observed for all fuels. At the low-load EOP, the SVO fuels showed larger particles for high EGR-rates. This effect also changed by increasing the engine-load to the mid-load EOP, wherein the particle size of the diesel fuel emissions is higher by applying elevated EGR-rates.}, language = {en} }